/Engine/Plugins/Runtime/GameplayAbilities/Source/GameplayAbilities/Public/AbilitySystemComponent.h
Updates the level of an already applied gameplay effect. The intention is that this is 'seemless' and doesnt behave like removing/reapplying
[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintCallable, BlueprintAuthorityOnly, Category=GameplayEffects) virtual void SetActiveGameplayEffectLevel ( [FActiveGameplayEffectHandle](API\Plugins\GameplayAbilities\FActiveGameplayEffectHandle) ActiveHandle, int32 NewLevel )